I used your method to test some MOSFETs and it made me look like a fool. The gate did not get fully turned on by touching drain and gate together. I complained about MOSFETs being defective because I calculated Rds without turning the gate on enough. One should run a separate wire from the power supply + to the gate lead (it should be at least 3v above power source voltage) while testing to get accurate Rds measurements.
Great info. One correction: The current will decrease slightly with each MOSFET in the circuit, thus the resistance calculations will end up slightly higher. You need to measure the current separately for each MOSFET and then apply Ohm's Law.
@@HighestRank No, there would be the same amount of meter reads for each measurement, so no more error by meter rounding would happen. I'm saying he needs to measure the amps for each separate MOSFET test instead of before any are in the circuit. It's still only one amperage reading per calculation just as before, only now it includes the actual current flowing with the MOSFET instead of the current without the MOSFET in series.
Both Drain current and Vds should be measured at the same time. The voltage drop Vds can affect the Drain current unless a constant current source is used.
Doesn't really matter - his numbers are spot on. I just tested some fake IRF540Ns myself with a milliohm meter and got .070 ohms Rds on. His results are good, even if you think his testing methodology is flawed.
The Source Drain resistance varie according to the voltage from the gate. You can found different value according to this. Minimal is 3,5, but if 20 volts are applied you can divide this resistance.
What you're saying is that the fake FETs are simply turning on too slowly, or that the real FETs are turning on too quickly, or that the fake FETs should have been tested at 3.5v for turn-on, or that the real FETs should have been fed 20v to see if they could handle the max. G-input regardless of low Rds.
I bought some mosfets from aliexpress to change them into an inverter. I'll tell you that the circuit originally uses CEP76139 (30v 75A N Channel) I wanted to put Irf1404 and they didn't work, then I bought CEP83A3 and it didn't work either and then I bought CEP93A3 and it didn't work. Finally I bought IRFP7540 from another platform and it worked. I don't know if it's because of an imitation mosfets or for another reason. These mosfets don't work. Do you have any experience? Please leave your comment. Thank you very much.
Another good test is to recognise the source... not as in source pin but supplier source. Pretty well 100% of devices coming from Ali, or Chinese Ebay sites especially those masquerading as local etc are fakes.. but from places like RS, Farnel etc... 100% genuine.
Hi, I think it is because I've used 1.75A... but in the datasheet, they used 16A. On 3:18 you can see a line "Id = 16A" (If I understand it correctly). I've tried higher current ( about 6A) and got much closer specs to the datasheet. It seems that on-resistance changes depending on the current that flows through MOSFET.
because the specs on the datasheet are for 3,5v source, and you applied 12v. When the grid is overvolted, the RDS significantly decrease, and will be better.
Is not kake but out of specification. Manufacter produce a large quantity. They make a sorting. Like sergio leone😂 the good, the bad and the ugly... The last makes injure for borf Thank you
hmm but I have borh! One a few fake ones and I ordered also an oryginal one to compare! When you look at it it is like you say but they work in very similar way!! I haven't noticed any difference! For me and for my purpose fake and oryginal are almost the same! The oryginal one came in a safer package and has slitely better parameteres and stability etc. but for someone who starts with electronics they would be the same! I am saying only about this MOSFET because it can happen also that the fake one is a totally crap as well...
Hi Electrical Projects, I just stumbled your channel and I have to say I'm really fascinated by your quick tutorials towards building miscellaneous electrical parts as a guide for someone like me who doens't know squat about such areas of composition. I'm just wondering how would you create a device for turning something on and off, and on and off again in a sequence at specific time intervals? And could you possibly create a video for such a device?
Hi, if you need to turn something on and off repeatedly you can just build something like "flip-flop flasher circuit", it is simple, it uses two transistors, you can add to it a relay and control anything... but if you need precise timings then you probably need Arduino, or if you need to turn something on/off at a specific time then you need ESP8266 to sync time from the internet. There are many videos with "flip-flop flashers" so I don't see a reason to make a video about it... but I want to build a device that after pressing a button turns a light bulb on for 10 - 500 seconds, and then turns it off.
@@ElectricalPro what if I'm trying to create something that mimic a person breathing? So inhaling and exhaling? It could take the form of a plastic bag and then something inside it that puts out air and suck air at specific time intervals to mimic an person's breathing pattern. Or even use a air pump putting out air for say 15 seconds and then turn off to allow the garbage bag with holes or something to release the contained air inside for 15 seconds. And right afterwards turn back on. How would it be done?
I don't know about mechanics, but the air pump will probably make a lot of noise. I only know electronics, not mechanics. Electrically you can control anything with a simple flip-flop circuit and relays... but if you need a delay between inhaling and exhaling, do it with Arduino. With Arduino, you can make it more realistic because you can add some randomness, and for example make some of the inhalings longer, or whatever you want.
I have bought IRF9610 some years ago, and are now using them in a design, these mosfets can dissipate 20 watts. However I have a test setup where the URF does drive a other mosfet and have a idle current of 10 mA and a voltage of 30 volts over it, calcaulating this make that the mosfet does dissipate 0.3 watts, normally I think even without a heatsink it can easely be save, however I did need a heatsink for it because it did get very hot without, so here, I can tell it is a fake mosfet, A shame Chinese supplyers does sell so much fakes I think we need to sanction that country. Oke you let see how we can see what is real, and that is the type with solder on connections, and copper is visible on the sides of the mosfet metal for cooling. Regards.
At the beginging [from0,25 to 0,32min.] when you show the fake and real mosfet, i noticed that on the fake one, the token IRF540N WAS WRITEN WITH GREATER NUMBER, O.K, so i concluded perhaps wrongly, that this point could drive someone that this will be the indice of the fake one. Now the question is .Is that notice correct and definit ? or not. I ask this in purpose to avoid the measurements. Thanks in advance ,i will apreciate your answer.
I tested a mosfet IRF3205 from China eBay and the result is 120 mVolt VDS , Ids 3.55A Rds 35mohm Vgs 12 v same results with other original bought from my local dealer... The datasheet 8 mohm for mine MOSFET IRF3205 is with very high pulsed current. Read all datasheet. Rds does not constant.... Change with Vgs current Vds... It is not so easy to measure...
I have the same situation testing a pair (fake marks IR) IRFP4768 from china measuring at 1A Ids gives on state 4.5V but it should be 0.0015V Rds(on)=15mohm. It is obvious that chinese products are made on cheap production for real packing.
Hi thanks for this video I have an hoverboard with a most problem and I didn't find a real one just a fake. Mine is IRF9530N and the one I did find is IRF9530 Did the fake is dangerous? and can she broke my hoverboard? Thanks❤
I have power inverter that went bad, I suspect mosfets. Theres 4 of them IRFP260M. Do any other letters on it matter or not? I have P514J? Cant find exact mosfets, only IRFP260M part, other letters dont match. What else could be wrong with it if not mosfets. It powers on, shows voltage, says for a sec it uses 500w, then goes to 0. Cant power anything. I checked with multimeter the outlet, voltage is all over the place. No blown fuses. Maybe transistors? Nothing blown. Caps all good, connection to bluetooth shows all good. No alarms.
bad traces(water damage), shorted windings in the miniature transformers(overheating), dry electrolytics which simply have died quietly and poly-metallized caps which can no longer heal themselves. Last might be a current-sensing shunt circuit with a cold solder joint or open resistor. I suspect that any discrete semiconductor shorts would have by now smoked themselves and stained the circuit board and cooked any components in the local vicinity...
Hi could I ask for your help on something please could you explain batteries in series switching parallel so I could change on parallel and run something on a higher vote
There is a good chance to buy fake on aliexpress, I don't know about ebay. I bought mine in a local store. Try to find a store that buys MOSFETs directly from the manufacturer.
PLEASE HELP ME ): I have a double battery ups and it's two MOSFETs are gone, It's because when i give too much load on my ups . And these are the MOSFETs prnt.sc/qwhbyd . Please tell me how can i change them Or If i buy any of irf3205 mosfet it's going to work or not ,,,,, prnt.sc/qwhfey
I brought 47N60C3 mosfets from China. They had Korea on some of them. Average source drain resistance 2.4 - 4 OHM no bull. I hope the Chinese find and execute such people, they are not worth the dust they are made off. Owe, they worked powering halogen bulbs but inductive circuit seem to fail in "on position"- much cursing! God - throw the cursing on their heads!
![Electrical Projects [CreativeLab]](http://yt3.ggpht.com/ytc/AIdro_nXuaCebPi8RjzINYxrETo1-K9WQerCEIndpQMoSs0BfQ=s48-c-k-c0x00ffffff-no-rj)
I used your method to test some MOSFETs and it made me look like a fool. The gate did not get fully turned on by touching drain and gate together. I complained about MOSFETs being defective because I calculated Rds without turning the gate on enough. One should run a separate wire from the power supply + to the gate lead (it should be at least 3v above power source voltage) while testing to get accurate Rds measurements.
Great info. One correction: The current will decrease slightly with each MOSFET in the circuit, thus the resistance calculations will end up slightly higher. You need to measure the current separately for each MOSFET and then apply Ohm's Law.
no that would introduce error by tolerance stacking because the meter rounds off every measurement and then you'd be adding even more rounded numbers.
@@HighestRank No, there would be the same amount of meter reads for each measurement, so no more error by meter rounding would happen. I'm saying he needs to measure the amps for each separate MOSFET test instead of before any are in the circuit. It's still only one amperage reading per calculation just as before, only now it includes the actual current flowing with the MOSFET instead of the current without the MOSFET in series.
Nice and simple. we need more videos like this. just small bits at at a time is easer to absorb
I am both very glad I found this video, and at the same time sad. Looks like I will need to order from reputable websites from now on.
This is the best rds video online
Both Drain current and Vds should be measured at the same time. The voltage drop Vds can affect the Drain current unless a constant current source is used.
Doesn't really matter - his numbers are spot on. I just tested some fake IRF540Ns myself with a milliohm meter and got .070 ohms Rds on. His results are good, even if you think his testing methodology is flawed.
Excelent information.
Now i know why my h bridge shorted my powe r supply every time
???
The Source Drain resistance varie according to the voltage from the gate. You can found different value according to this. Minimal is 3,5, but if 20 volts are applied you can divide this resistance.
What you're saying is that the fake FETs are simply turning on too slowly, or that the real FETs are turning on too quickly, or that the fake FETs should have been tested at 3.5v for turn-on, or that the real FETs should have been fed 20v to see if they could handle the max. G-input regardless of low Rds.
A simple wire tester showed me gate and drain are conducting, much brighter led than real one, bought that very 540n last month from my trusted shop !
so since the the voltage is low that means high current and low resistance (ohms law)
Very important information for a technician, thanks you
Good Video 👍 Please make a video on Dual Axis SOLAR TRACKER Project !!
I have fake mosfets but they work great
That's absolutely amazing! They must be saving a few tenths of a penny at best!
Same here, from 3 different local dealers...
I bought some mosfets from aliexpress to change them into an inverter. I'll tell you that the circuit originally uses CEP76139 (30v 75A N Channel) I wanted to put Irf1404 and they didn't work, then I bought CEP83A3 and it didn't work either and then I bought CEP93A3 and it didn't work. Finally I bought IRFP7540 from another platform and it worked. I don't know if it's because of an imitation mosfets or for another reason. These mosfets don't work. Do you have any experience? Please leave your comment. Thank you very much.
great video . also make a video about measruing the Cd capcitace to check authenticity
Oke ty i have the fake ones on order 🙁 but are they stell good fore little amp ratings? Like 5 a at 24 at max? Im using a heatsink on it
fake or Qc rejected but still working?
does a bigger "fake" = a smaller real?
for 1/10 the price it's still a good deal.
very good. wow understood even by novice like me. thank you. my fake chinese bought irfp260 at 117mh and the original at .039
Now I know why my some devices blasted !!!!!!!
Another good test is to recognise the source... not as in source pin but supplier source.
Pretty well 100% of devices coming from Ali, or Chinese Ebay sites especially those masquerading as local etc are fakes.. but from places like RS, Farnel etc... 100% genuine.
A quiz question, why did I get better specs than in the datasheet?
Specs correct for minor manufacturing differences?
Hi, I think it is because I've used 1.75A... but in the datasheet, they used 16A. On 3:18 you can see a line "Id = 16A" (If I understand it correctly). I've tried higher current ( about 6A) and got much closer specs to the datasheet.
It seems that on-resistance changes depending on the current that flows through MOSFET.
@@ElectricalPro great
data sheet are typical specs, since it is better that means past the test
because the specs on the datasheet are for 3,5v source, and you applied 12v. When the grid is overvolted, the RDS significantly decrease, and will be better.
Very good, thanks!
Is not kake but out of specification. Manufacter produce a large quantity. They make a sorting.
Like sergio leone😂
the good, the bad and the ugly...
The last makes injure for borf
Thank you
nice demonstration... subscribed
Who made the counterfeit mosfets?
No one actually knows. But if I say China, that about covers it, along with everything else they counterfeit, copy and steal.
that was great video
What do you suggest buying authentic solid state devices?
Thanks❤❤😮😊😊
hmm but I have borh! One a few fake ones and I ordered also an oryginal one to compare! When you look at it it is like you say but they work in very similar way!! I haven't noticed any difference! For me and for my purpose fake and oryginal are almost the same! The oryginal one came in a safer package and has slitely better parameteres and stability etc. but for someone who starts with electronics they would be the same! I am saying only about this MOSFET because it can happen also that the fake one is a totally crap as well...
Hi Electrical Projects, I just stumbled your channel and I have to say I'm really fascinated by your quick tutorials towards building miscellaneous electrical parts as a guide for someone like me who doens't know squat about such areas of composition. I'm just wondering how would you create a device for turning something on and off, and on and off again in a sequence at specific time intervals? And could you possibly create a video for such a device?
Hi, if you need to turn something on and off repeatedly you can just build something like "flip-flop flasher circuit", it is simple, it uses two transistors, you can add to it a relay and control anything... but if you need precise timings then you probably need Arduino, or if you need to turn something on/off at a specific time then you need ESP8266 to sync time from the internet. There are many videos with "flip-flop flashers" so I don't see a reason to make a video about it... but I want to build a device that after pressing a button turns a light bulb on for 10 - 500 seconds, and then turns it off.
@@ElectricalPro what if I'm trying to create something that mimic a person breathing? So inhaling and exhaling? It could take the form of a plastic bag and then something inside it that puts out air and suck air at specific time intervals to mimic an person's breathing pattern. Or even use a air pump putting out air for say 15 seconds and then turn off to allow the garbage bag with holes or something to release the contained air inside for 15 seconds. And right afterwards turn back on. How would it be done?
I don't know about mechanics, but the air pump will probably make a lot of noise. I only know electronics, not mechanics. Electrically you can control anything with a simple flip-flop circuit and relays... but if you need a delay between inhaling and exhaling, do it with Arduino. With Arduino, you can make it more realistic because you can add some randomness, and for example make some of the inhalings longer, or whatever you want.
I have bought IRF9610 some years ago, and are now using them in a design, these mosfets can dissipate 20 watts. However I have a test setup where the URF does drive a other mosfet and have a idle current of 10 mA and a voltage of 30 volts over it, calcaulating this make that the mosfet does dissipate 0.3 watts, normally I think even without a heatsink it can easely be save, however I did need a heatsink for it because it did get very hot without, so here, I can tell it is a fake mosfet, A shame Chinese supplyers does sell so much fakes I think we need to sanction that country. Oke you let see how we can see what is real, and that is the type with solder on connections, and copper is visible on the sides of the mosfet metal for cooling. Regards.
You are right 👍
I came to this video after burning new MOSFET
P55nf06 new fake
Old ones works fine original
So nice thanks
how identifly fake IGBT ? Can use like cicuit for IGBT s?
At the beginging [from0,25 to 0,32min.] when you show the fake and real mosfet, i noticed that on the fake one, the token IRF540N WAS WRITEN WITH GREATER NUMBER, O.K, so i concluded perhaps wrongly, that this point could drive someone that this will be the indice of the fake one. Now the question is .Is that notice correct and definit ? or not. I ask this in purpose to avoid the measurements. Thanks in advance ,i will apreciate your answer.
can you provide a circuit diagram for this tes?
the irf3205z mosfet is written z3205z at lcsc site. is it that the way they write it or are they fake? also the company is named IT and not IR
Very good
Good 👍 👍 👍
I tested a mosfet IRF3205 from China eBay and the result is 120 mVolt VDS , Ids 3.55A Rds 35mohm Vgs 12 v same results with other original bought from my local dealer... The datasheet 8 mohm for mine MOSFET IRF3205 is with very high pulsed current. Read all datasheet. Rds does not constant.... Change with Vgs current Vds... It is not so easy to measure...
Do you have kink please or name of seller ?
you measured the current whithouts mosfet and divided voltage drop with that value, it is wrong. u should measure current through the mosfet.
Miss how u can say one.seventyfive
I have the same situation testing a pair (fake marks IR) IRFP4768 from china measuring at 1A Ids gives on state 4.5V but it should be 0.0015V Rds(on)=15mohm. It is obvious that chinese products are made on cheap production for real packing.
Hi thanks for this video
I have an hoverboard with a most problem and I didn't find a real one just a fake.
Mine is IRF9530N and the one I did find is IRF9530
Did the fake is dangerous? and can she broke my hoverboard?
Thanks❤
I have power inverter that went bad, I suspect mosfets. Theres 4 of them IRFP260M. Do any other letters on it matter or not? I have P514J? Cant find exact mosfets, only IRFP260M part, other letters dont match.
What else could be wrong with it if not mosfets. It powers on, shows voltage, says for a sec it uses 500w, then goes to 0. Cant power anything. I checked with multimeter the outlet, voltage is all over the place. No blown fuses. Maybe transistors? Nothing blown. Caps all good, connection to bluetooth shows all good. No alarms.
bad traces(water damage), shorted windings in the miniature transformers(overheating), dry electrolytics which simply have died quietly and poly-metallized caps which can no longer heal themselves. Last might be a current-sensing shunt circuit with a cold solder joint or open resistor. I suspect that any discrete semiconductor shorts would have by now smoked themselves and stained the circuit board and cooked any components in the local vicinity...
Load test - If it catches fire it's fake.
Hi could I ask for your help on something please could you explain batteries in series switching parallel so I could change on parallel and run something on a higher vote
higher *voltage
thank u
You should have measured the current for each mosfet.
Good
I have a burned mosfet from ST, it's a P80NF55 @ CZ OYN 6 MAR 839! can you explain what are these digits mean! thanks
it means you're lucky to still see the part numbers: many FETs burn off their IDs as they melt.
The fake heaat sink is iron but in original is copper and magnet don.t grab it but fake magent grab it
LOL...Ever heard a word called "Tolerance"?!
where did you buy real irf540n mos fet? aliexpress or ebay ?
There is a good chance to buy fake on aliexpress, I don't know about ebay. I bought mine in a local store. Try to find a store that buys MOSFETs directly from the manufacturer.
@@ElectricalPro
O.K. Thank you for reply.
Please,you would have add the schematic of your connection
It is only a serial connection between source 12v and bulb
YOU TUBE - Robotizado con CD 4017, NE 555 Pilotos Andre
So where we can buy real mosfet ???
Mouser, Farnell, Digikey
А как найти русский вариант канала?
no circuit schematic................bad
Thubnail is Lying
My mosfet show 4.5 v why
You need to connect the gate with the red probe (supply +) once, then connect red probe to drain (make sure the red probe does not touch the gate).
PLEASE HELP ME ):
I have a double battery ups and it's two MOSFETs are gone,
It's because when i give too much load on my ups .
And these are the MOSFETs prnt.sc/qwhbyd .
Please tell me how can i change them Or If i buy any of irf3205 mosfet it's going to work or not ,,,,,
prnt.sc/qwhfey
Spasiba
91mOhm is better than mine.... I have some fake 540s that have 1Ohm. and irfz44n that have 2Ohms.
My mosfet even more worst resistance,its 50 ohm
OK, so I'm not the only one. My eBay MOSFETs had 5 ohms Rds. Totally useless for my repair job. Thanks for sharing.
zero point fifteen ? zero point one five
hello, how about IRFB4227? same connection with your testing?
You mean pinout?, yes, it has the pinout.
Almost every mosfet or transistor is BCE or GDS, and even if it isn’t, the last pin is E or S 99.99% of the time
I think you are from Czech Republic, protože tvuj prizvuk je tam slyset
I am from Ukraine :)
😂
I brought 47N60C3 mosfets from China. They had Korea on some of them. Average source drain resistance 2.4 - 4 OHM no bull. I hope the Chinese find and execute such people, they are not worth the dust they are made off. Owe, they worked powering halogen bulbs but inductive circuit seem to fail in "on position"- much cursing! God - throw the cursing on their heads!
1:22 data shit
You've not had a shit until you've had a data shit!
Excelent. ..chinese fets fake..